Update build system for better Clang behavior on Mac.

Change-Id: I1813954681b670807d7e3faaf6d5f5a769cc5f2e

core/clang/config.mk

@@ -33,10 +33,10 @@ CLANG_CONFIG_UNKNOWN_CFLAGS := \
   -Wno-unused-but-set-parameter
 
 # Clang flags for all host rules
-CLANG_CONFIG_HOST_EXTRA_ASFLAGS := --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG)
-CLANG_CONFIG_HOST_EXTRA_CFLAGS := --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG)
-CLANG_CONFIG_HOST_EXTRA_CPPFLAGS := --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG)
-CLANG_CONFIG_HOST_EXTRA_LDFLAGS := --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG)
+CLANG_CONFIG_HOST_EXTRA_ASFLAGS :=
+CLANG_CONFIG_HOST_EXTRA_CFLAGS :=
+CLANG_CONFIG_HOST_EXTRA_CPPFLAGS :=
+CLANG_CONFIG_HOST_EXTRA_LDFLAGS :=
 
 # Clang flags for all target rules
 CLANG_CONFIG_TARGET_EXTRA_ASFLAGS :=

core/clang/x86_common.mk

@@ -13,17 +13,21 @@ HOST_ARCH_DESCRIPTOR_FOR_CLANG := i686-linux
 endif
 
 CLANG_CONFIG_x86_LINUX_HOST_EXTRA_ASFLAGS := \
+  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
   --sysroot=$(HOST_TOOLCHAIN_FOR_CLANG)/sysroot
 
-CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CFLAGS :=
+CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CFLAGS := \
+  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
 
 CLANG_CONFIG_x86_LINUX_HOST_EXTRA_CPPFLAGS :=   \
+  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
   --sysroot=$(HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
   -isystem $(HOST_TOOLCHAIN_FOR_CLANG)/$(HOST_ARCH_DESCRIPTOR_FOR_CLANG)/include/c++/4.6.x-google \
   -isystem $(HOST_TOOLCHAIN_FOR_CLANG)/$(HOST_ARCH_DESCRIPTOR_FOR_CLANG)/include/c++/4.6.x-google/$(HOST_ARCH_DESCRIPTOR_FOR_CLANG) \
   -isystem $(HOST_TOOLCHAIN_FOR_CLANG)/$(HOST_ARCH_DESCRIPTOR_FOR_CLANG)/include/c++/4.6.x-google/backward \
 
 CLANG_CONFIG_x86_LINUX_HOST_EXTRA_LDFLAGS := \
+  --gcc-toolchain=$(HOST_TOOLCHAIN_FOR_CLANG) \
   --sysroot=$(HOST_TOOLCHAIN_FOR_CLANG)/sysroot \
   -B$(HOST_TOOLCHAIN_FOR_CLANG)/$(HOST_ARCH_DESCRIPTOR_FOR_CLANG)/bin \
   -B$(HOST_TOOLCHAIN_FOR_CLANG)/lib/gcc/$(HOST_ARCH_DESCRIPTOR_FOR_CLANG)/4.6.x-google \

core/combo/HOST_darwin-x86.mk

@@ -123,7 +123,9 @@ define transform-host-o-to-shared-lib-inner
 $(hide) $(PRIVATE_CXX) \
         -dynamiclib -single_module -read_only_relocs suppress \
         $(HOST_GLOBAL_LD_DIRS) \
-        $(HOST_GLOBAL_LDFLAGS) \
+	$(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
+	   $(PRIVATE_HOST_GLOBAL_LDFLAGS) \
+	) \
         $(PRIVATE_ALL_OBJECTS) \
         $(addprefix -force_load , $(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \
         $(call normalize-host-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
@@ -140,9 +142,11 @@ define transform-host-o-to-executable-inner
 $(hide) $(PRIVATE_CXX) \
         -Wl,-rpath,@loader_path/../lib \
         -o $@ \
-        $(PRE_LION_DYNAMIC_LINKER_OPTIONS) -headerpad_max_install_names \
+        $(PRE_LION_DYNAMIC_LINKER_OPTIONS) -Wl,-headerpad_max_install_names \
         $(HOST_GLOBAL_LD_DIRS) \
-        $(HOST_GLOBAL_LDFLAGS) \
+	$(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
+	   $(PRIVATE_HOST_GLOBAL_LDFLAGS) \
+	) \
         $(call normalize-host-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
         $(PRIVATE_ALL_OBJECTS) \
         $(call normalize-host-libraries,$(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \